Uridine is a pyrimidine nucleoside and is essential in the synthesis of ribonucleic acids and tissue glycogens such as UDP glucose and UTP glucose. Prior medical uses of uridine alone include treatment of genetic disorders related to deficiencies of pyrimidine (synthesis such as orotic aciduria. Choline, a dietary component of many foods, is part of several major phospholipids that are critical for normal membrane structure and function. Choline is included with lipid emulsions that deliver extra calories and essential fatty acids to patients receiving nutrition parenterally.